The present invention broadly relates to recirculating-type liquid coating or paint supply systems of the types in widespread commercial use for keeping heavily-bodied pigments suspended in the liquid coating composition thereby promoting uniformity in the quality and color of the paint film applied to a substrate. Recirculating paint supply systems conventionally comprise a mixing tank equipped with suitable agitation for maintaining the liquid coating composition uniformly mixed and a pump for transferring the liquid coating composition under a desired pressure to an automatic or manual spray nozzle. A suitable return line of a reduced pressure is provided for returning the excess quantity of paint back to the mixing tank for recirculation. A flow control or restrictor device is conventionally employed at the inlet of the spray nozzle or spray gun which is adjustable so as to control the actual quantity of liquid coating composition for discharge through the spray nozzle.
In large commercial installation, such as in spray booths of the type employed for painting automobile bodies and the like, each spray booth or station is generally equipped with a plurality of individual paint supply systems of different color and/or type. Typically, twelve or more individual colored paint supply systems are installed at each spray station to achieve the required flexibility. It will be appreciated that each such system includes a pressure supply line and a return line such that in a station equipped with twelve separate systems, a total of twenty-four conduits or tubes are required which makes the spray station somewhat cumbersome from an operating standpoint. The supply tubes are normally about 15 to 20 feet in length and are of flexible structure extending between the main supply header and main return header to the spray nozzle.